diff --git a/reproman/distributions/debian.py b/reproman/distributions/debian.py
index 6c9ad9b35..77f9ee85a 100644
--- a/reproman/distributions/debian.py
+++ b/reproman/distributions/debian.py
@@ -100,12 +100,22 @@ class DebianDistribution(Distribution):
     """
 
     apt_sources = TypedList(APTSource)
-    packages = TypedList(DEBPackage)
+    _packages = TypedList(DEBPackage)
     version = attrib()  # version as depicted by /etc/debian_version
 
     _collection_attribute = 'packages'
 
 
+    @property
+    def packages(self):
+        return self._packages
+
+
+    @packages.setter
+    def packages(self, value):
+        self._packages = value
+
+
     def initiate(self, session):
         """
         Perform any initialization commands needed in the environment.